Process for the preparation of metahalosulfonylbenzoyl halide



United States Patent 3,290,370 PROCESS FOR THE PREPARATION OF META-HALOSULFONYLBENZOYL HALIDE Edward D. Weil, Lewiston, N.Y., and Robert J.Lisanke,

Sr., Pitman, N.J., assignors to Hooker Chemical Corggoraition, NiagaraFalls, N.Y., a corporation of New or No Drawing. Filed May 27, 1963,Ser. No. 283,571 6 Claims. (Cl. 260-544) The present invention isconcerned with a process for the preparation of m-halosulfonylbenzoylhalides. More specifically, the present invention relates to thereaction of benzotrihalide and a sulfonating agent.

It has been known that sulphonyl chlorides are formed by the action ofchlorosulfonic acid on aromatic hydrocarbons and that the yields ofsulphonyl chlorides obtained may be increased by increasing thechlorosulfonic acid used, as is disclosed in Berichte der deutschenChemischen Gesellschaft, volume 42, page 1802.. Therefore, in the largescale manufacture of sulphonyl chlorides of aromatic hydrocarbons,chlorosulphonic acid is generally employed in a large excess, or toavoid this necessity, the sulphonylchlorides are prepared from thesulphonic acids by reaction with phosphorus chlorides.

It has also been known that sulphonyl chlorides of aromatic carboxylicacids are obtained by the action of chlorosulphonic acid in large excessupon aromatic carboxylic acids, as, for example, in the conversion of anaromatic carboxylic acid chloride into the sulphonylchloride of thearomatic carboxylic acid by means of a large excess (14 mols) ofchlorosulphonic acid (J. Chem. Soc. (London), 1934).

These processes yield chlorosulfonyl aroyl acids. Further reaction withan acylating agent such as PCl S Cl and the like, is required to convertthe product to chlorosulfonyl aroyl chloride. Ingeneral, therefore,these processes are multi-step, requiring the utilization of costlyreagents and equipment.

In accordance with the present invention benzotrihalide is reacted witha sulphonating agent in the presence of heat. The reaction may beexemplified by the following equation:

' o ox heat xso n 2 SOzX wherein X is a halogen selected from the groupconsisting of chlorine and bromine. It is surprisingly found that nosubstantial excess of halosulfonic acid is required, and that thedibasic acid dihalide is obtained directly in good yield and undermoderate conditions. This result is especially surprising in view of thewell known deactivating effect of a trihalomethyl group towardelectrophilic substitution on the aromatic ring. Illustrative examplesof the benzotrihalide starting reagent include benzotrichloride andbenzotribromide. Among the sulfonating agents which may be utilized topractice the present invention are chlorosulfonic acid and bromosulfonicacid.

The reaction is generally accomplished by heating and stirring mixturesof the reactants until the evolution of hydrogen halide ceases. Reactiontemperatures will vary with the reactivity of the particular startingreactants. Such a temperature will generally be in the range of fromabout 50 degrees centigrade to about 200 degrees centigrade. Thepreferred temperature employed in the practice of the present inventionis in the range of about 60 degrees centigrade to about 150 degreescentigrade.

The reagents are generally utilized in substantially equimolar amounts,but may be varied if desired. Generally ice the molar ratio ofhalosulfonic acid to benzotrihalide is in the range of less than 1:1 toabout 6:1 with the preferred range being about 2 moles of halosulfonicacid to about 1 mole of benzotrichloride.

Pressures employed in effecting the processes of the present inventionare conveniently about atmospheric but subor super-atmospheric pressuresmay be employed. The pressure can obviously be as low as the vaporpressure of the halosulfonic acid starting reactant at operatingtemperatures. Pressures as high as those obtained in autoclaves e.g.1,000 atmospheres, can be employed.

A solvent is not generally necessary but one can be used to moderate orfacilitate the reaction. Among the solvents which may be used aresulfonation-resistant solvents such as chlorobenzenes, nitrobenzenes,nitroalkanes, chloroalkanes, and the like. Other solvents of high enoughboiling point to maintain the required reaction temperature and which donot react with either of the selected starting reagents may be utilized.

In a preferred embodiment benzotrichloride is added to chlorosulfonicacid in the presence of heat until the evolution of hydrogen halide hasbeen completed and the resulting mixture is then purified, which may bedone conveniently by distillation or other suitable means. The reactionmay be illustrated by the following equation:

heat m 0180 11 S0201 21101 In order that those skilled in the art maybetter understand the present invention, the manner in which it may bepracticed, the following specific examples are given.

Example 1.-Pr0cess for preparing m-chlorosulfonylbenzoylchloride frombenzotrichloride 543 grams (4.65 moles) of chlorosulfonic acid wereheated to a temperature of about 60 degrees centigrade in a flaskequipped with mechanical stirrer, reflux condenser, thermometer andaddition funnel, and 392 grams (2 moles) benzotrichloride were addeddropwise to the warm chlorosulfonic acid with stirring. The addition wasaccompanied by evolution of hydrogen chloride gas, which continued forabout two hours after the addition was completed. After the addition wascomplete the temperature of the reaction mixture was brought to about130 degrees centigrade for about two hours, until little or no furtherevolution of hydrogen chloride wa observed. Distillation of the mixtureresults in about a percent yield of metachlorosulfonyl benzoyl chloride,of boiling point of 161-3 degrees centigrade at 9 mm. mercury.Approximately 60 parts of chlorosulfonic acid is recovered in theforeshot, along with a little HCl and S0 Example 2 Similar to Example 1,196 grams benzotrichloride was added over a two hour period to 175 gramsof chlorosulfonic acid at to 127 degrees centigrade with agitation. Thetemperature was maintained at 120 degrees centigrade for 2.5 hours andthe product was distilled. 193 grams of rnetachloros-ulfonyl benzoylchloride was obtained as identified by infrared analysis.

While there have been described various embodiments of the invention,the methods and elements described are not intended to be understood aslimiting the scope of the invention, as it is realized that changestherewithin are possible, and it is further intended that each elementrecited in any of the following claims is to be understood as referringto all equivalent elements for accomplishing substantially the sameresults in substantially the same or equivalent manner, it beingintended to cover the invention broadly in whatever form its principlemay be utilized.

What is claimed is: 1. A process for the preparation of a compound ofthe formula COX SOzX

wherein X is a substituent selected from the group consisting ofchlorine and bromine comprising contacting a compound of the formulawherein X is a substituent selected from the group consisting ofchlorine and bromine with a compound of the formula wherein X is asubstituent selected from the group consisting of chlorine and bromine.

2. A process in accordance with claim 1 wherein X is chlorine.

3. A process for the preparation of a compound of the formula COXwherein X is a substituent selected from the group consisting ofchlorine and bromine comprising contacting a compound of the formulawherein X is a substituent selected from the group consisting ofchlorine and bromine with a compound of the formula wherein X is asubstituent selected from the group consisting of chlorine and brominein the presence of heat.

4. A process in accordance with claim 3 wherein the substituent X ischlorine.

5. A process in accordance with claim 3 wherein the temperature employedis from about 60 degrees :centigrade References Cited by the ExaminerUNITED STATES PATENTS 1,557,154- 11/1925 George 260544 2,273,974 2/ 1942Meiser 260507 X 3,203,987 8/1965 Hoefle 260544 X Y LORRAINE A.WEINBERGER, Primary Examiner.

RICHARD K. JACKSON, Assistant Examiner.

1. A PROCESS FOR THE PREPARATION OF A COMPOUND OF THE FORMULA